Atlas Obscura continues their 31 Days of Halloween series with a scary story from Louisiana history.

In 1831, Madame Delphine LaLaurie and her third husband Dr. Leonard Louis Nicolas LaLaurie bought a fine house in downtown New Orleans. Madame LaLaurie made a lovely home and entertained the city's elite inside. But she developed as reputation for being abusive to her slaves when people noticed how skinny they were. She once had to forfeit nine of them for a cruelty charge. But New Orleans society had no idea how cruel she was until the fire.

Driven to suicide by LaLaurie's abuse, the 70-year-old cook (who was emaciated, despite being chained to the stove) set fire to the mansion on April 10, 1834. As the flames spread, a crowd gathered to assist LaLaurie and her guests escape the blaze. As LaLaurie rushed about salvaging her coats and jewels and possessions from the fire, the crowd began to wonder, why weren't her servants helping her? LaLaurie shrugged these questions off. As smoke consumed the upper levels, moans and screaming became audible from the street, and a group of over a dozen men formed to help the slaves, who'd clearly been locked away. Delphine staunchly refused to give the men the keys, and so they found their way through the burning home to the attic door, kicking it in to free the trapped servants. There is no way they could have anticipated what lay behind the door.